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From: Jiri Slaby <jirislaby@kernel.org>
To: Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
	gregkh@linuxfoundation.org, akpm@linux-foundation.org,
	stefani@seibold.net
Cc: linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] tty: nozomi: Fix a resource leak in an error handling function
Date: Mon, 10 May 2021 11:51:16 +0200	[thread overview]
Message-ID: <749cb98d-07d6-740e-1d2d-46306520089b@kernel.org> (raw)
In-Reply-To: <4f0d2b3038e82f081d370ccb0cade3ad88463fe7.1620580838.git.christophe.jaillet@wanadoo.fr>

On 09. 05. 21, 19:22, Christophe JAILLET wrote:
> A 'request_irq()' call is not balanced by a corresponding 'free_irq()' in
> the error handling path, as already done in the remove function.
> 
> Add it.
> 
> Fixes: 9842c38e9176 ("kfifo: fix warn_unused_result")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

Reviewed-by: Jiri Slaby <jirislaby@kernel.org>

> ---
> I also wonder if the loop above is correct. The 'i < MAX_PORT' looks really
> spurious to me.
> 'tty_port_destroy' can be called twice for the same entry (once before
> branching in the error handling path, and once in here) and
> 'tty_unregister_device'/'tty_port_destroy' will be called on entries
> that have not been 'tty_port_init'ed or 'tty_port_register_device'd.
> I don't know if it may be an issue.

Yes. The fail path handling is very broken there. Both the code of 
err_free_tty label, and of the err_free_kfifo label. The loops should 
have been _something_ (I didn't invest much thinking into it, so it's 
likely wrong) like:
for (i--; i--; ) {
    ...
}


> ---
>   drivers/tty/nozomi.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/tty/nozomi.c b/drivers/tty/nozomi.c
> index 9a2d78ace49b..b270e137ef9b 100644
> --- a/drivers/tty/nozomi.c
> +++ b/drivers/tty/nozomi.c
> @@ -1420,6 +1420,7 @@ static int nozomi_card_init(struct pci_dev *pdev,
>   		tty_unregister_device(ntty_driver, dc->index_start + i);
>   		tty_port_destroy(&dc->port[i].port);
>   	}
> +	free_irq(pdev->irq, dc);
>   err_free_kfifo:
>   	for (i = 0; i < MAX_PORT; i++)
>   		kfifo_free(&dc->port[i].fifo_ul);
> 

thanks,
-- 
js
suse labs

      parent reply	other threads:[~2021-05-10  9:51 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-09 17:22 [PATCH] tty: nozomi: Fix a resource leak in an error handling function Christophe JAILLET
2021-05-10  6:35 ` Dan Carpenter
2021-05-10  9:51 ` Jiri Slaby [this message]

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